Semiconductor device and method of fabricating the same

Abstract

Disclosed are a semiconductor device and a method of fabricating the same. The method includes forming a first GaN layer, a sacrificial layer and a second GaN layer on a GaN substrate, wherein the sacrificial layer has a bandgap narrower than those of the GaN layers; forming a groove penetrating the second GaN layer and the sacrificial layer; growing GaN-based semiconductor layers on the second GaN layer to form a semiconductor stack; forming a support substrate on the semiconductor stack; and removing the GaN substrate from the semiconductor stack by etching the sacrificial layer. Accordingly, since the sacrificial layer is etched using the groove, the support substrate can be separated from the semiconductor stack without damaging the support substrate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is the National Stage of International Application No. PCT / KR2012 / 010852, filed on Dec. 13, 2012, and claims priority from and the benefit of Korean Patent Application No. 10-2011-0134130, filed on Dec. 14, 2011, Korean Patent Application No. 10-2011-0135513, filed on Dec. 15, 2011, Korean Patent Application No. 10-2012-0026879, filed on Mar. 16, 2012, and Korean Patent Application No. 10-2012-0026948, filed on Mar. 16, 2012, which are hereby incorporated by reference for all purposes as if fully set forth herein.BACKGROUND[0002]1. Field[0003]The present invention relates to a semiconductor device and a method of fabricating the same, and more particularly, to a light emitting diode and a method of fabricating the same.[0004]2. Discussion of the Background[0005]In general, since Group III nitrides such as gallium nitride (GaN) and aluminum nitride (AlN) have excellent thermal stability and a direct-transition-type energy ...

AI Technical Summary

Benefits of technology

The present invention provides a method for improving the light extraction efficiency of LEDs. This is achieved by using a transparent oxide layer with a concavo-convex pattern to extract light from the LED. By growing semiconductor layers on a GaN substrate with low dislocation density, the LED exhibits improved light emitting efficiency. Additionally, the LED includes a polarization-reducing semi-polar semiconductor layer and is fabricated using a miscut GaN substrate, which results in reduced fabrication costs. The invention also utilizes a miscut GaN substrate to reuse it and reduce fabrication costs.

Problems solved by technology

However, the epitaxial layer grown on the heterogeneous substrate has a relatively higher dislocation density due to lattice mismatch between the epitaxial layer and the growth substrate and a difference in thermal expansion coefficient between the epitaxial layer and the growth substrate.

There is a limitation in improving the light emitting efficiency of the LED using the epitaxial layer having such a high dislocation density.

Therefore, the recombination rate of electrons and holes is lowered, and there is a limitation in improving light emitting efficiency.

However, since the GaN substrate is homogeneous with the epitaxial layer grown thereon, it is difficult to fabricate the high-efficiency LED with the vertical structure by separating the GaN substrate from the epitaxial layer.

However, the growth of the GaN-based compound semiconductor layer on a-plane or m-plane has many problems to be solved, and therefore has not been widely applied yet.

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